Step plate



FIG. 1 is a perspective view of a step plate showing my new design;

FIG. 2 is a rear side elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right end elevational view thereof; and

FIG. 6 is a left end elevational view thereof. 

The ornamental design for a step plate, substantially as shown. 